Think again

New Delhi. Dec. 19: With every puff they take, smokers might need to watch out for polonium, the radioactive element that was used to kill Russian spy Alexander Litvinenko.

Several scientific studies suggest that radioactive polonium which was found to be present in cigarette smoke decades ago may be delivering radiation into the lungs of smokers.

Researchers at the Institute of General Chemistry in Italy have just analysed polonium concentration in 17 of the most-frequently smoked cigarette brands in Italy.

Their results, set to be published in the January 2007 issue of the journal Health Physics, show that polonium concentrations ranged from 6.84 mBq to 17.48 mBq per cigarette. Bq, or Becquerel, is a standard unit of radioactivity.

“The lung dose from inhalation of cigarette smoke is much higher than the lung dose from inhalation of atmospheric polonium or lead,” the Italian researchers said in their report.

A study from the Institute of Nuclear Technology in Greece, published earlier this year, in the Journal of Environmental Radioactivity, said the inhalation dose of smokers is 12 times higher than for non-smokers.

Scientists had first reported polonium in cigarette smoke 40 years ago by demonstrating the presence of radioactive material in the tissues of cigarette smokers.

A research team at the Argonne National Laboratory in the US had shown in the mid-1960s that polonium levels in rib bones of cigarette smokers were about twice the levels in non-smokers.

Two years ago, atomic energy scientists in Egypt estimated polonium activity in smoke by analysing its activity in fresh tobacco, wrapping paper, fresh filter, ash and post-smoking filters.

They calculated that those who are smoking 20 cigarettes per day are inhaling on average 123 mBq per day of polonium.

Scientists suspect that cigarette smoking may lead to an increase in internal radiation dose and thus contribute to the instances of lung cancer observed among smokers.

The study from Greece has shown that dry tobacco leaves may also contain polonium.